Wait a minute. The intake manifold says performer 289 on it....the one bolted to the engine?????
I used to have the same manifold on my wifes car, I don't believe Edelbrock made a perfromer 289 for a 351 W!
Edelbrock makes the Performer 289 intake,
Then the regular performer intake,
then the Performer RPM and so on...
Buddy I think you have a regular 302 base motor! If thats the case the carb you have is fine.
If it is a real 351 you can still use it if it is a REAL conservitive engine. If its got some work to it, it will most likely need a 700-750 cfm carb or bigger depending on mods.
See if you can list some part#'s that are on the block to verify engine. Show some pics too, if you can.
Let us know.